Services are system processes running in the background which wait for incoming requests. When a process wants to communicate with a service, it first needs to get a handle to the named service, and then it can communicate with the service via inter-process communication (each service has a name up to 8 characters).

Handles for services are retrieved from the service manager port, "sm:", and are released via svcCloseHandle or when a process is terminated or crashes. Manager service "sm:m" also exists. Services are an abstraction of ports, they operate the same way except regular ports can have their handles retrieved directly from a SVC. Services are also able to limit the number of handles given to other processes.